Detergent dispenser having an overcenter spring door actuator

ABSTRACT

A dishwasher detergent dispenser in which the dispenser is held closed by an overcenter spring which, upon being urged past its overcenter position by electrically actuated means such as a bimetal, also provides the force to open the detergent dispenser.

United States Patent Inventor Edward H. Donselman Columbus, Ohio Appl.No. 795,670

Filed Jan. 31, 1969 Patented June 15, 1971 Assignee WestinghouseElectric Corporation Pittsburgh, Pa.

DETERGENT DISPENSER HAVING AN OVERCENTER SPRING DOOR ACTUATOR 7 Claims,6 Drawing Figs.

U.S. Cl 222/54, 49/], 222/70, 222/557 Int. Cl 867d 5/08 Field of Search222/70, 54,

References Cited UNITED STATES PATENTS Rusho Kendt Krzewina Seal Duncanet al.... Wrightenberry Primary Examiner- Stanley H. Tollberg AssistantExaminerDavid A. Scherbel Attorneys-F. H. Henson and E. C. ArenzABSTRACT: A dishwasher detergent dispenser in which the dispenser isheld closed by an overcenter spring which, upon being urged past itsovercenter position by electrically actuated means such as a bimetal,also provides the force to open the detergent dispenser.

PATENTEU JUN 1 5 I97! SHEET 1 0F 2 FIG.|.

FIGS.

INVENTOR Edward H. Donselmon ATTORNEY PATENTED JUN 1 5 I97! SHEET 2 IF 2FIGS.

FIG. 4.

DETERGENT DISPENSER HAVING AN OVERCENTER SPRING DOOR ACTUATOR BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention pertains tothe art of actuating dispensers in washing machines such as dishwashers.

2. Description of the Prior Art Examples of detergent dispensers fordishwashers of the general character to which this invention isapplicable, and which include a solenoid or a bimetal for controllingdispensing are U.S. Pat. Nos. 3,344,957, 3,212,675; and 3,012,696. It isnoted that while these patents are representative of typicalarrangements, neither they, nor any other prior art of which I am aware,teaches or suggests the concept with which my invention is concerned.

SUMMARY OF THE INVENTION In the currently preferred form of myinvention, a dispenser in the dishwasher tub has a cover attached to apivotal shaft also carrying lever means to which an overcenter spring isattached to bias the cover toward a closed position when the spring ison one side of the shaft centerline, and an open position when on theother side of the centerline. Actuating means, such as a bimetalenergized at the proper time during the washing cycle, urges the levermeans from a position in which the cover is closed to a position inwhich the overcenter spring is shifted sufficiently past a centeredposition over the shaft that it will then provide the force to move thedispenser cover to a fully open position. Thus the actuating means doesnot function in any sense as a latch, the overcenter means serving bothto hold the dispenser closed, and to provide the force to move it to afully open position after the actuating means has initiated thedispenser opening operation.

DRAWING DESCRIPTION FIG. I is a elevational view of a dispenserarrangement according to the invention;

FIG. 2 is a partly broken and partly sectioned side view of portions ofthe dispenser arrangement of FIG. 1;

FIG. 3 is a view similar to FIG. I but showing the parts in the positioncorresponding to the dispenser being open to release the detergent;

FIG. 4 is a face view of one example of the detergent dispenseraccording to the invention with the cover open and corresponding to theposition of the mechanism of FIG. 3;

FIG. 5 is a sectional view corresponding to one taken along the line V-Vof FIG. 1; and

FIG. 6 is a fragmentary elevational view of an embodiment employing asolenoid actuator.

PREFERRED EMBODIMENTS The invention will be described in connection witha dishwasher of the type having a swing down door for access to the tubfor loading and unloading, and in which the controls are mounted in thedoor. The detergent receptacle illustrated as one example is of the typein which the receptacle itself is fixed and is provided with a covermovable between an open and closed position. It will be appreciated thatthe invention is not limited to any particular type of detergentreceptacle, nor to its particular location.

Referring to FIGS. I and 2, the detergent cup 10 is mounted on theinside face ofan inner panel 12 which forms one wall of the dishwashingtub when the door is closed, the interior space of the tub beingindicated by numeral I4 located to the right of the cup in FIG. 2. Thecup is provided with a pivotal cover 16 fixed to a shaft 18 for rotationtherewith, the shaft being journaled in the cup material adjacent acorner of the cup. The shaft extends through an opening in the innerpanel, an opening in the dispenser mechanism mounting bracket 20, ax-

ially through a compression spring 22, and has a lever arm 24 attachedto its noncircular outer end so that rotation of the lever arm willeffect rotation of the shaft, and vice versa. The compression springinsures that the cover 16 is pulled reasonably tightly against the openface of the cup when the cover is closed. An O-ring 26 seals between theshaft and a bushing 28 which may be formed as an integral portionof thecup.

The mounting bracket 20 is fixed to the outwardly facing face of theinner panel 12 and mounts the dispenser actuating mechanism in the space30 in between the inner panel and the outer finished panel 32 of thedishwasher door. The bracket has one turned-up tab 34 adjacent the lowerright corner of the bracket as shown in FIG. 1, and another turned-uptab 36 closer to the pivotal axis of the shaft. The tab 34 secures oneend of a tension spring 38 which has its other end secured to the leg 40of the bellcrank-shaped lever 24. When the detergent dispenser cover 16is closed, the actuating mechanism is in the position illustrated inFIG. 1 in which the axis of the spring 38 lies slightly to the right ofthe axis of the shaft 18. This is the slightly overcenter position ofthe spring 38 which results in the spring force being transmittedthrough the lever and shaft to urge the dispenser cover in a directionholding the cover closed.

The other leg 42 of the lever arm 24 is disposed, as shown in FIG. I,for engagement by actuating means which triggers the opening of thedispenser cup. In that illustrated embodiment, the currently preferredactuating means in the form of an electrically energized bimetal 44 isshown. The bimetal which has its left end portions secured in aninsulating and adjustment block 46 and its right end free to engage andbear against the lever leg 42 when the bimetal is energized andaccordingly heated. The bimetal is of the double leg type as shown inFIG. 5. The extreme left ends of the bimetal legs are attached to asource of electrical power so that a circuit can be completed throughthe bimetal itself. The dissimilar metals of the bimetal are arranged sothat upon sufficient heating of the bimetal above ambient temperaturethe right end of the bimetal will move downwardly to push the leg 42 ofthe lever in that direction which tends to rotate the lever arm 24 in acounterclockwise direction as indicated by the arrow in FIG. 1. When thebimetal has pushed the lever arm sufficiently that the axis of thespring 38 has moved past center to the left of the axis of the shaft I8sufficiently, the tension in spring 38 provides the force which movesthe cover 16 to a fully open position as illustrated in FIG. 4. Theposition of the parts of the actuating mechanism position on FIG. 3corresponds to the dispenser cover being fully open and with the leg 42being stopped by the tab 36. The cover 16 is returned to a closedposition after the dishwasher cycle has been completed by manuallyrotating the cover 16 to a closed position which in turn moves the lever24 back to its FIG. I position and again cocks the spring 38. The coveris prevented from being moved past its fully closed position andaccordingly moving the lever arm 24 back past its FIG. I position by theabutment of the offset edges 48 of the cover and cup (FIG. 2).

From the foregoing it will be appreciated that when the overcenterspring 38 (FIG. I) has its longitudinal axis lying in any range ofpositions to the right of the axis of shaft 18, the biasing force willurge the lever arm 24 serving as the dispenser condition controllingmeans in a clockwise direction. Thus, it may be said that when thedispenser condition controlling means occupies any position in the rangebetween a closely approaching-closed position (i.e., spring 38 axisintersecting shaft I8 axis), and a dispenser-closed position, thebiasing means urges the controlling means toward the dispenser-closedposition. Conversely, when the spring 38 axis is to the left of the axisof shaft 18, the controlling means is beyond that range.

The relation of the bimetal to the lever arm 24 is adjustable by movingthe adjusting member 50 which is attached to the insulating andadjusting block 46. Then the screw 52 may be tightened down to hold thebimetal in its adjusted position.

In an alternative arrangement shown in H0. 6, the bimetal is replaced byother electrically actuated means such as a solenoid 54 disposed so thatupon energization thereof it provides the force to move the lever 24sufficiently that the tension spring 38 will complete the opening of thecover. Another alternative arrangement would utilize a mechanicallinkage with the timer to move the lever 24.

Upon reflection it will be appreciated that the overcenter springfurnishes the biasing force both for keeping the cover closed and alsofor moving the cover to an open position following the initial nudge bythe electrically actuated means. Thus any positive latching is avoidedand the cover 16 may be readily opened and closed without any sensationby the user of forcing the mechanism. Also, when the electricallyactuated means is a bimetal, the timer knob as typically used on mostdishwashers may be turned through an entire cycle manually withoutdumping the detergent when a restarted cycle is desired.

As will be appreciated by those versed in the art, the bimetal isconnected in an electrical circuit so that the bimetal is energized atthe proper time during the dishwashing cycle to open the cover andrelease the detergent. Typically, a timer is used for controlling thevarious parts of the dishwashing cycle and the timer contacts are simplyarranged to provide energization of the bimetal at the proper timeduring the cycle.

I claim as my invention:

1. in a washing machine having a dispenser having opposite open andclosed conditions corresponding to respectively opposite positions ofdispenser condition controlling means, the improvement comprising:

biasing means for urging said controlling means to said oppositepositions, said biasing means being disposed to urge said controllingmeans toward a position corresponding to a dispenser closed conditionwhen said controlling means is in a range of positions between a closelyapproaching-closed and a dispenser-closed position, and to urge saidcontrolling means toward a position corresponding to a dispenser opencondition when said controlling means is in a position beyond saidrange;

said controlling means is pivotally mounted on a shaft;

said biasing means comprises a spring functioning as an overcenterspring by having an axis lying along a line which moves across the axisof said shaft as said controlling means is moved between its oppositepositions;

and

actuating means for moving said controlling means beyond said range at aselected time during a washing cycle of said machine.

2. In a machine according to claim I wherein: said overcenter springcomprises a tension spring.

3. In a washing machine according to claim 1 wherein:

said actuating means comprises electrically actuated means in the formof a bimetallic element disposed relative to said controlling means tomove said controlling means beyond said range upon a period ofenergization of said bimetallic element.

4. According to claim 1 wherein:

said actuating means comprises electrically actuated means in the formof a solenoid disposed relative to said controlling means to move saidcontrolling means beyond said range upon energization of said solenoid.

5. In a dishwashing machine having a washing tub:

a washing aid dispenser receptacle in said tub including means movablebetween a position in which said receptacle is closed and anotherposition in which said receptacle is open;

rotatable shaft means having said movable means fixed thereto forrotation therewith;

lever means fixed to said shaft for rotation therewith;

an overcenter spring connected to said lever means, said spring beingdisposed relative to said lever means for urging said movable meanstoward a position corresponding to said receptacle being closed whensaid movable means is in a range of positions between closelyapproachingclosed and a closed position, and for urging said movablemeans to a position corresponding to said receptacle being open whensaid movable means is in a position beyond said range; and

actuating means for moving said lever beyond said range at a preselectedtime during the washing cycle.

6. in a washing machine according to claim 5 wherein:

said movable means comprises a receptacle cover rotatable with saidshaft means and said lever means.

7. In a machine according to claim 6 wherein:

said actuating means comprises a bimetallic element disposed to engagesaid lever upon a sufficient period of energization of said element tomove said lever means beyond said range.

1. In a washing machine having a dispenser having opposite open andclosed conditions corresponding to respectively opposite positions ofdispenser condition controlling means, the improvement comprising:biasing means for urging said controlling means to said oppositepositions, said biasing means being disposed to urge said controllingmeans toward a position corresponding to a dispenser closed conditionwhen said controlling means is in a range of positions between a closelyapproaching-closed and a dispenser-closed position, and to urge saidcontrolling means toward a position corresponding to a dispenser opencondition when said controlling means is in a position beyond saidrange; said controlling means is pivotally mounted on a shaft; saidbiasing means comprises a spring functioning as an overcenter spring byhaving an axis lying along a line which moves across the axis of saidshaft as said controlling means is moved between its opposite positions;and actuating means for moving said controlling means beyond said rangeat a selected time during a washing cycle of said machine.
 2. In amachine according to claim 1 wherein: said overcenter spring comprises atension spring.
 3. In a washing machine according to claim 1 wherein:said actuating means comprises electrically actuated means in the formof a bimetallic element disposed relative to said controlling means tomove said controlling means beyond said range upon a period ofenergization of said bimetallic element.
 4. According to claim 1wherein: said actuating means comprises electrically actuated means inthe form of a solenoid disposed relative to said controlling means tomove said controlling means beyond said Range upon energization of saidsolenoid.
 5. In a dishwashing machine having a washing tub: a washingaid dispenser receptacle in said tub including means movable between aposition in which said receptacle is closed and another position inwhich said receptacle is open; rotatable shaft means having said movablemeans fixed thereto for rotation therewith; lever means fixed to saidshaft for rotation therewith; an overcenter spring connected to saidlever means, said spring being disposed relative to said lever means forurging said movable means toward a position corresponding to saidreceptacle being closed when said movable means is in a range ofpositions between closely approaching-closed and a closed position, andfor urging said movable means to a position corresponding to saidreceptacle being open when said movable means is in a position beyondsaid range; and actuating means for moving said lever beyond said rangeat a preselected time during the washing cycle.
 6. In a washing machineaccording to claim 5 wherein: said movable means comprises a receptaclecover rotatable with said shaft means and said lever means.
 7. In amachine according to claim 6 wherein: said actuating means comprises abimetallic element disposed to engage said lever upon a sufficientperiod of energization of said element to move said lever means beyondsaid range.